In a conventional metal container for a carbonated beverage such as a soft drink or beer, the ‘pop top’ closure is integrated into the can end and incorporates a mechanical lever to facilitate the initial fracture, fracture propagation and ultimate displacement of the sealing panel formed integrally with the can end, to create a dispensing mouth through which container contents may be dispensed. This has proven to be a reliable, effective, and inexpensive means of providing an initial seal and dispensing means for carbonated drink products in metal containers. Once the dispensing means is deployed and the dispensing mouth is opened, however, there is no provision for reclosing or resealing the container as would be desirable to prevent spills particularly if the beverage container is in motion as would be the case if it is situated in a moving vehicle, to prevent contamination through the open dispensing mouth including entry of airborne dust or contaminants or insects, and to provide a gas tight sealing means to prevent the escape of the carbonating gases present in the liquid, an absence of which results in a ‘flat’ beverage which is generally thought to be unappealing and generally results in the beverage being discarded.
Further, the conventional ‘pop top’ actuating lever is considered by many, especially women with long and/or decorated fingernails, to be a less than optimal solution because it requires the user to slip their fingernail under the actuating lever which may cause damage to a polished or decorated fingernail, and also requires that the maximum force be applied during the initial displacement of the actuating lever which is when the dispensing mouth die-line fracture is initiated, by lifting up on the actuating lever with only the fingernail engaged under the edge of the actuating lever. This places a large amount of strain on the fingernail and the fingernail bed and is generally regarded as painful or unpleasant by many users, particularly if they must perform the task repeatedly as would be the case for a bartender or someone working in a retail or commercial environment where beverages in metal containers are regularly served. The actuating lever is so designed as to provide substantial mechanical advantage to facilitate the initial fracture of the dispensing mouth die-line, but there is inadequate mechanical engagement or ‘purchase’ with the user's finger at the point where maximum effort is required due to the close proximity of the actuating lever to the can end at the time the fracture is initiated.
For these reasons, it has long been thought desirable to incorporate a means of reclosing and preferably resealing metal containers for carbonated beverages as well as a means of improving purchase for initial opening to reduce or eliminate user discomfort.
There have been many attempts at a solution to the problems of resealing a metal beverage container once the initial seal has been broken, and to improving the purchase for initial opening of the dispensing means. The most rudimentary solution to the problem of reclosing a metal container is the use of a separate lid, such as a molded plastic lid which is so designed as to ‘snap’ onto the seam at the top of the metal container where the can end is joined to the can body. Such lids do provide a means of reclosing but do not provide a gas tight means of resealing.
Another solution to the problem of resealing a metal container for carbonated beverages is the development of fundamentally new closure means for metal containers. One example of such a new closure means is the Ball Resealable End or BRE which employs a complex, multi-layer plastic and rubber rotary seal and dispensing mechanism. The BRE has seen limited commercial use. Another example of a new closure means is the XO end which incorporates a sliding plastic closure means and a large diameter sealing wafer located inside the metal container.
The most rudimentary solution to the problem of inadequate purchase for the actuating lever on a conventional pop top can is the use of a specialized tool designed to slip under the actuating lever in lieu of the user's fingernail to initiate displacement of the lever, fracturing of the dispensing mouth die-line and displacement of the sealing panel.
One area of deficiency generally present in all of the proposed solutions to redesigned closures is high cost, particularly in comparison to the conventional pop top end.
Another deficiency generally present in all of the proposed solutions to redesigned closures is that some do not reliably provide a gas tight seal.
Yet another deficiency generally present in all of the proposed solutions to redesigned closures is that they present a disagreeable mouth feel to users.
A further deficiency generally present in all of the proposed solutions to redesigned closures is that they incorporate a large quantity of plastic inside of the can which cannot be removed unless the can is cut open, thereby creating a problem if one desires to recycle the can.
Yet another deficiency generally present in all of the proposed solutions to redesigned closures is that they will not run on conventional metal container filling and sealing equipment lines and require very costly special tooling in order to be used.
One area of deficiency generally present in all of the proposed solutions to the problem of improving purchase for opening existing pop top closures is the necessity of purchasing, and then remembering to keep proximal to any metal beverage containers which one may wish to open, the special tool described above.
A further area of deficiency present in conventional pop top can closures as well as all proposed solutions to the problems inherent therein is the vulnerability of the closure means to environmental contamination wherein the closure is unprotected from ambient conditions from the time it is initially filled, through shipping, warehousing, distribution, retail display, and ultimate purchase. This potentially exposes the entire metal container, particularly the dispensing mouth where the user will place their lips to consume the product, and in the case of the conventional pop top closure the sealing panel, which is displaced downwards to be immersed in the can contents, to unsanitary and potential dangerous or harmful contaminants.
While there are presently a number of proposed solutions to the problem of improving cleanliness and hygiene of closures, improving purchase on metal container closure means and providing gas tight resealability, none have been conceived or implemented to permit an easy to use, cost effective, recyclable, compatible with existing filling and sealing equipment solution which would be optimal for the application.